Hard steel articles
AssigneeBorgWarner Inc.
InventorsYumin Wang, Yoshito Hanayama, Doug Fornell, Naosumi Tada, Kunihiko Mishima
Life of this patent
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Abstract
Chain parts and other steel articles are provided with hard, wear-resistant carbide coatings by tumbling them in a heated retort with a particulate mix which includes a source of vanadium and/or niobium. The steel substrate comprises a steel having at least 0.2% carbon, preferably 0.7-1.2%. Where the chromium content of the steel is 4-12%, preferably 4-8%, the chemical deposition process includes drawing a small amount of chromium from the steel substrate into the vanadium or niobium carbide coating, where it is distributed substantially homogeneously, helping to provide adhesion strength to the coating.
Claims8
An article comprising a hard coating comprising at least one Group 5 metal carbide and including 1-3% chromium carbide interspersed substantially homogeneously therein, and a core of steel including 0.7% to 1.2% by weight carbon and 4-8% chromium.
Dependencies are inferred from the claim text.